Not applicable.
Not applicable.
1. Field of the Invention
The invention relates to a method for the manufacture of individual pipe sections of a pipe formed by a product pipe and of at least one channel running along the product pipe, particularly a heat channel in which the product pipe and the channel are fitted with an insulation enclosed with a jacket pipe and a pipe manufactured in that manner.
2. Description of Related Art
Practical applications often require pipes to be heated because the products to be transported within the product pipe exhibit appropriate flowability only at a certain temperature. The heating of the pipes is generally achieved with an accompanying heating system consisting of a heat pipe attached to the product pipe used to transport the product. German Patent No. DE-PS 43 14 761, for example, describes a method for the manufacture of individual pipe sections of a pig pipe. The patent describes a method in which the product pipe is fitted with an additional heating pipe through which the heating of the product to be transported in the product pipe is achieved with steam piped at a high pressure as the heating medium.
Practical applications have shown, however, that the heat transfer between the heating and product pipe is in many cases insufficient due to the linear contact area between the two pipes and due to the fact that steam cannot be used as the heating medium when the product to be transported in the product pipe should not come into contact with water for safety reasons. Furthermore, the known form for the heating channels is disadvantageous for pipes that are not straight, because the fitting of an additional heating pipe to the product pipe is difficult to achieve from a manufacturing point of view, particularly at sharp bends.
It is an object of the invention to provide a method for the manufacture of individual pipe sections of a pipe such that good heat transfer to the product pipe is achieved and any channel shape can be run along the product pipe in a cost-effective manner.
The invention is a method for the manufacture of individual pipe sections including a product pipe having a jacket surface and at least one channel running along the jacket surface of the product pipe including the following steps:
a) Arranging a core that exhibits at least the outside contour of the desired channel on the surface of the product pipe such that the channel to be formed upon the removal of the core will be immediately adjacent to the surface of the product pipe and approximately parallel to the product pipe.
b) Inserting the product pipe with the core into a jacket pipe; and
c) Filling the jacket pipe with an insulating mass that exhibits a flowability only during processing.
An advantage of the invention is that any channel type may be manufactured along the product pipe such that it is in direct contact with the surface of the product pipe.
Accordingly, it is a feature of the invention to easily pull an electric heat conductor through the channel arranged in the manner of the invention. It is also possible to run heating gas through the channel. In addition to utilizing the channel as a heating channel, it is also possible to use it for receiving a detector cable or a so-called xe2x80x9csniffing pipexe2x80x9d which can detect leaks in the product pipe.
These and other objects, advantages, and features of this invention will be apparent from the following description.